 | Frederick Walter Simms - 1834 - 124 pages
...degree, but it is doubtful whether an angle can be measured by it even to that degree of accuracy : c is a prism, which the observer looks through in...by which it can be turned over to the side of the compass-box, that being its position when put into the case. The sight-vane has a fine thread stretched... | |
 | Basil Jackson - 1847 - 410 pages
...compass- card, in such a manner as to make the divisions on the card seem a continuation of the thread ; and the division with which the thread coincides,...azimuth of whatever object the thread may bisect. A hinge-joint connects the prism with the box, and enables it to be turned over in a convenient position... | |
 | Sir Henry Edward Landor Thuillier - 1851 - 826 pages
...degree, but it is doubtful whether an angle can be measured by it even to that degree of accuracy: c is a prism, which the observer looks through in...the thread may bisect. The prism is mounted with a hinge-joint, D, by which it can be turned over to the side of the compass-box, that being its position... | |
 | William Mitchell Gillespie - 1855 - 436 pages
...the card is usually divided to \ or I of a degree. C is a prism, which the observer looks through. The perpendicular thread of the sight-vane, E, and...thread coincides, when the needle is at rest, is the " Bearing" of whatever object the thread may bisect, ie is the angle which the line of sight makes... | |
 | Benjamin Pike - 1856 - 412 pages
...a narrow vertical slit ; the other, o, which is turned to the object, is a similar slip, having au oblong aperture containing a fine thread, passing...divisions on the card appear together on looking through th< prism, and the division with which the thread coincides when the needle is at rest, is the magnetic... | |
 | William Mitchell Gillespie - 1856 - 478 pages
...the card is usually divided to | or \ of a degree. C is a prism, which the observer looks through. The perpendicular thread of the sight-vane, E, and...thread coincides, when the needle is at rest, is the " Bearing" of whatever object the thread may bisect, ie is the angle which the line of sight makes... | |
 | William Mitchell Gillespie - 1857 - 538 pages
...the card is usually divided to \ or \ of a degree. C is a prism, which the observer looks through. The perpendicular thread of the sight-vane, E, and...thread coincides, when the needle is at rest, is the " Bearing" of whatever object the thread may bisect, ie is the angle which the line of sight makes... | |
 | William Mitchell Gillespie - 1868 - 530 pages
...the card is usually divided to J or 1 of a iegree. 0 is a prism, which the observer looks through. The perpendicular thread of the sight-vane, E, and the divisions on the card, appear tec/ether on looking through the prism, and the division with which the thread coincides, when the... | |
 | William Davis Haskoll - 1868 - 252 pages
...weather. p is the prism through which the surveyor observes. The perpendicular wire of the sight vane, v, and the divisions on the card, appear together on looking through the prism ; that particular division on the card, with which the wire coincides, when the needle is at rest,... | |
 | William Mitchell Gillespie - 1869 - 550 pages
...the card is usually divided to \ or \ of a degree. C is a prism, which the observer looks through. The perpendicular thread of the sight-vane, E, and...thread coincides, when the needle is at rest, is the " Bearing" of whatever object the thread may bisect, ie is the angle which the line of sight makes... | |
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The perpendicular thread of the sight-vane, E, and the divisions on the card, appear together on looking through the prism, and the division with which the thread coincides, when the needle is at rest, is the 
